HK1065744B - Electric rotational tool driving switch system - Google Patents

Description

Driving switch mode of electric rotary tool

Technical Field

The present invention relates to an electric rotary tool such as an electric screwdriver, and more particularly, to a drive switch system for an electric rotary tool, in which a drive switch capable of performing drive control suitable for work content is set when the electric rotary tool is used, the operation is simplified, and an appropriate screwing work of a screw or the like can be always performed easily and safely.

Background

Conventionally, as an electric rotary tool such as an electric screwdriver (ドライバ one) driven by an electric motor, there has been known an electric rotary tool configured as follows: the driving of the electric motor is started by operating the driving switch, and the rotary tool such as a screwdriver bit is driven by the driving of the electric motor to perform a work such as screwing, and the load torque generated on the rotary tool following the end of the work is detected by the torque detecting means, and when the detected load torque reaches a torque value preset by the combination of the torque adjusting spring and the cam, the state is detected by the torque setting automatic stopping means, and the driving of the rotary tool is automatically stopped.

For example, in the case of an electric screwdriver or the like, the following configuration is proposed and implemented: when a strong reaction force load is applied to a screwdriver bit when a screw is tightened, a state in which a predetermined torque value is reached is detected by a clutch mechanism that operates with a tightening torque set in advance, and the clutch mechanism is operated to temporarily block the coupling between the output shaft of the electric motor and the screwdriver bit. Further, an electric screwdriver or the like which is disposed so that the state is detected by a limit switch or the like when the clutch mechanism is operated and the driving of the electric motor is stopped is also put into practical use (japanese patent publication No. 60-13798).

There is also proposed an automatic current interruption device for an electric rotary tool in which the operation of the clutch mechanism is detected by a magnet piece and a magnetic force detecting element (hall element) to interrupt the current to an electric motor, thereby stopping the driving of the electric motor (japanese patent publication No. 60-3960).

Further, there has been proposed an electric screwdriver or the like including an automatic energization/shutoff device (japanese patent publication No. 57-43389) which is configured such that a switching circuit is provided in a power supply circuit of an electric screwdriver or the like having a driver bit rotationally driven by an electric motor, and when a predetermined tightening torque is reached near the end of screwing, a load current flowing to the power supply circuit at the time of driving the electric motor increases to an overload current of a predetermined value or more, and therefore, this state is detected, the supply of a driving current to the electric motor is shut off, and thereafter, when a predetermined time elapses, the supply of the driving current to the electric motor is resumed, and further, a switching mechanism is provided in an armature circuit of the electric motor, and when the supply of the driving current to the electric motor is shut off by the switching circuit, the armature circuit of the electric motor is short-circuited to perform regenerative braking, the electric motor is momentarily stopped. Since the switching circuit is kept in the OFF state for a certain period of time, the switching circuit is automatically restored to the ON state at the time of the next tightening operation, and the electric motor is driven, thereby providing a function of immediately performing the next tightening operation.

In this type of electric rotary tool, an external AC (alternating current) power supply (commercial power supply) is generally used for driving and controlling the electric motor, and in this case, a control unit having an AC/DC power conversion function, a torque control function, and the like is used to obtain a power output suitable for driving the electric motor from the external AC power supply. When a general small-sized DC motor is used as the electric motor, the control unit is configured as a unit independent from the electric rotary tool, and is connected between the AC power supply and the electric rotary tool to control the driving of the electric motor.

However, in the DC motor, there has been proposed and put into practical use an electric motor for an electric rotary tool, which is a brushless motor having excellent characteristics such as no contact, noise prevention, high torque miniaturization, high-speed rotation, and extended life and has the advantage of being free from maintenance. Unlike the case of the DC motor, a driving circuit for generating a rotating magnetic field is required for driving and controlling the brushless motor. The drive circuit may be constituted by a magnetic sensor (generally, a hall element) for detecting the magnetic pole position of the magnet rotor, a drive coil excited to apply a rotational force in a predetermined direction in accordance with the position of the magnetic pole of the magnet rotor, and an exclusive IC circuit for controlling the application of the rotational force to the magnetic sensor and the drive coil.

The drive circuit thus constructed can be housed and arranged in the grip portion case of the electric rotary tool together with the circuit having a torque control function and the like, and a compact circuit arrangement can be achieved. Therefore, when a brushless motor is used, the control unit formed independently of the electric rotary tool is not required, only the AC/DC converter is required, and the drive circuit and the like are incorporated in the electric rotary tool to make the structure simple, thereby facilitating the operation.

Further, in this type of electric rotary tool, a push operation system and a lever operation system are adopted as a drive switch for starting driving of the electric motor as a device that is easy to operate. The former pressing operation method is arranged such that, when an operator grips an electric rotary tool and slightly presses a work object such as a screw by bringing a rotary tool such as a screwdriver bit protruding from a tip thereof into contact with the work object, the rotary tool is elastically displaced in the axial direction, and by this displacement, a drive switch such as a microswitch is turned on, and the electric motor is connected to a required power source, and the drive of the electric motor is started. In the latter control lever operation method, when an operator grips an electric rotary tool and brings a rotary tool such as a screwdriver bit protruding from a tip end thereof into contact with a work object such as a screw, the operator presses a switch control lever provided arbitrarily in a grip portion of the electric rotary tool to displace the switch control lever, whereby a drive switch such as a microswitch is turned on by the displacement, and the electric motor is connected to a required power supply to start driving of the electric motor.

As described above, in the conventional electric rotary tool, since the micro switch or the like is used as the drive switch for starting the driving of the electric motor, sparks or the like are generated at the switch contact point during the operation thereof, which has a disadvantage that not only the contact point is worn but also various disadvantages are caused to peripheral electronic parts, electronic devices, electronic circuits, and the like. Therefore, the mechanical switch mechanism has not only a structural limitation in terms of miniaturization and a prolonged life, but also a number of limitations in its structural configuration that make the entire electric rotary tool compact.

In addition, in the conventional electric rotary tool, the drive switch is configured to select either one of the pressing operation mode and the lever operation mode, and for example, when the pressing operation mode is to be changed to the lever operation mode or vice versa according to a change in work content, it is necessary to prepare an electric rotary tool having different drive switch modes of the two operation modes in advance. Therefore, if the configuration is such that the drive switches having the two different operation modes are incorporated in 1 electric rotary tool and one of the two operation modes can be selected and used as necessary, the range of use of the electric rotary tool can be increased and the operation of the electric rotary tool can be simplified.

As a result of extensive studies and extensive trial and error, the present inventors have found that the electric motor can be easily rotationally driven by attaching the magnet to a switch lever provided on a shaft supporting the rotary tool or on a grip of the electric rotary tool, using a combination of the magnet and a magnetic sensor as a drive switch, connecting the magnetic sensor to an energizing circuit of the electric motor, disposing the magnet at a position displaced from the magnet, and operating the rotary tool by pressing down (i.e., a pressing operation mode) or by pressing down the control lever (i.e., a lever operation), and opening the energizing circuit by bringing the magnet close to the magnetic sensor to sense a magnetic force.

In this case, if the drive switch of the above-described configuration uses the hall element as the magnetic sensor and the energizing circuit uses the IC circuit, it is possible to configure an extremely small and compact configuration, and therefore, it is confirmed that the drive switches of the above-described pressing operation mode and the lever operation mode can be easily provided for 1 electric rotary tool. In particular, when a brushless motor is used as the electric motor, the drive switch and the drive control circuit of the electric motor can be compactly housed and arranged in the grip portion case of the electric rotary tool, and the operation can be simplified.

In addition, when the driving switches having two different operation modes are provided, the driving switches are arranged to be switchable so that either operation mode can be selectively used, so that the efficiency of the work can be improved and the safety of the work can be improved. Further, when the operation is completed, the conventional torque detecting device and the torque setting automatic stopping device are applied, and the operation of screwing a screw or the like is appropriately completed, so that the driving of the electric motor is stopped, and the operation is quickly and smoothly shifted to the standby state for the next operation.

Accordingly, an object of the present invention is to provide a drive switch system for an electric rotary tool, which can selectively perform drive control by a desired pressing operation system or lever operation system according to each operation content when the electric rotary tool is used, can always achieve efficiency of a tightening operation of a screw or the like appropriately, can make the operation simple, and can sufficiently improve safety.

Disclosure of Invention

In order to achieve the above object, a drive switch system of an electric rotary tool according to the present invention includes: an electric motor; a rotary tool for screwing the screw, coupled to an output shaft of the electric motor; a drive switch for driving the electric motor and starting the operation by a rotary tool; a torque detection device that detects a load torque generated in the rotary tool as the work ends; and a torque setting automatic stop device which stops the driving of the rotary tool when the load torque reaches a preset torque value, wherein the drive switch of a press operation mode and the drive switch of a control lever operation mode are combined with a magnet and a magnetic sensor, respectively, wherein the drive switch of the press operation mode performs an opening operation by pressing and displacing the rotary tool against a screw operation object, and the drive switch of the control lever operation mode performs an opening operation by pressing and displacing a switch control lever provided in a grip portion of the electric rotary tool; the magnetic sensors are connected to an energizing circuit of the electric motor, the energizing circuit is configured to energize the electric motor with the magnetic sensor which is operated by pressing to sense magnetic force, and a circuit is configured in such a manner that the electric motor is energized by a magnetic sensor which is operated by a control lever to perform a magnetic force sensing operation, and in a joint portion between a grip portion housing of the electric rotary tool and the switch control lever, a magnet is provided in a part of the switch lever, a magnetic sensor is disposed on the side of the grip housing so as to face the magnet, and a selection switch is provided, the selection switch can automatically select and switch the energizing circuit for starting the driving of the electric motor by a pressing operation mode when the switch control lever is removed and starting the driving of the electric motor by a control lever operation mode when the switch control lever is installed.

Preferably, a brushless motor is used as the electric motor, and a drive control circuit of the brushless motor and an energization circuit thereof are all housed in a grip portion case of the electric rotary tool.

Preferably, an externally operable forward/reverse switch is provided in a part of the grip housing of the electric rotary tool, and when the electric motor is switched from forward rotation to reverse rotation, an energizing circuit is configured such that the driving of the electric motor by the push operation method is disabled, and an energizing circuit is configured such that the driving of the electric motor can be started only by the lever operation method.

Preferably, in the case of using the clutch mechanism as the torque detection device incorporated in the grip housing of the electric rotary tool, the torque adjustment mechanism acting on the clutch mechanism is disposed to slightly protrude obliquely with respect to the support shaft of the rotary tool protruding vertically downward from the grip housing.

Drawings

Fig. 1 is a schematic configuration diagram showing an embodiment of a drive switch type electric rotary tool according to the present invention.

Fig. 2 is an enlarged explanatory view of a main part thereof, showing a structure of a drive switch by a press operation method in the electric rotary tool shown in fig. 1 and an operation state thereof.

Fig. 3 is a main part explanatory view showing another embodiment of the drive switch mode selection changeover switch in the electric rotary tool shown in fig. 1.

Fig. 4 is a wiring block diagram showing an example of a power-on circuit configuration of an electric motor implementing a drive switch mode in the electric rotary tool shown in fig. 1.

Fig. 5 is a wiring block diagram showing a modification of the energization circuit of the electric motor implementing the drive switch system in the electric rotary tool shown in fig. 4.

Fig. 6 is a schematic configuration diagram showing another embodiment of the electric rotary tool having the drive switch system according to the present invention.

Description of the symbols

10 electric rotary tool

11 grip part case

12 electric motor

12a motor output shaft

14 rotating tool

16 speed reducing mechanism

18 torque detector

19 drive shaft

20 shaft coupling

22 drill bit chuck mechanism

23 support shaft

23a support the end of the shaft

24 drive control circuit

24a drive circuit

24b torque setting automatic stop circuit

25 spring device

26 switch control lever

28 positive and negative change-over switch

30 drive switch (push operation mode)

31a magnet

31b magnetic sensor

32 drive switch (control rod operation mode)

33a magnet

33b magnetic sensor

34 selection change-over switch

35a magnet

35b magnetic sensor

36 AC/DC converter

38 torque setting automatic stop circuit

40 control unit

42 torque adjusting mechanism

Detailed Description

Next, referring to the drawings, the present invention relates to a drive switch mode of an electric rotary tool

The examples are described in detail below.

Fig. 1 is a view showing an embodiment of a drive switch type electric rotary tool according to the present invention. That is, in fig. 1, reference numeral 10 denotes an electric rotary tool such as an electric screwdriver, which is disposed such that an electric motor 12 including a brushless motor or the like is incorporated in the electric rotary tool 10, a rotary tool 14 such as a screwdriver bit or the like is removably attached to a tip portion thereof, and the rotary tool 14 is driven by the driving of the electric motor 12 to perform a work such as screwing.

A speed reduction mechanism 16, for example, a planetary gear mechanism or the like, is provided on the motor output shaft 12a of the electric motor 12, a torque detection device 18 is provided between the speed reduction mechanism 16 and the rotary tool 14, and a load torque generated in the rotary tool 14 during a work such as screwing is detected. In this case, the bit chuck mechanism 22 is coupled to the tip of the drive shaft 19 protruding from the torque detection device 18 coupled to the motor output shaft 12a of the electric motor 12 via the speed reduction mechanism 16 via the coupling 20, and the rotary tool 14 such as a screwdriver bit is removably mounted on the bit chuck mechanism 22.

In the electric rotary tool 10 of the present embodiment configured as described above, the drive control circuit 24 is housed and arranged in the necessary space in the grip portion case 11 of the electric rotary tool 10, and the drive control circuit 24 is configured by: a drive circuit 24a that drives the electric motor 12; and a torque setting automatic stop circuit 24b for detecting a load torque generated in the rotary tool 14 following the completion of the operation such as tightening by the torque detection device, and stopping the driving of the rotary tool 14, that is, the driving of the electric motor 12, when the detected load torque reaches a preset torque value.

An externally operable switch lever 26 is attached to one side portion of the outer periphery of the grip housing 11 of the electric rotary tool 10, and a forward/reverse switch 28 for appropriately switching the forward/reverse rotation of the electric motor 12 is appropriately attached.

In the present embodiment, the magnetic sensor 31b, which is configured by combining the magnet 31a and the hall element, is configured as a drive switch 30 of a push operation type in which the rotary tool 14 is pressed and displaced by abutting against a work object such as a screw, thereby performing an ON operation. In this case, as shown in detail in fig. 2, the drive switch 30 of the push operation type inserts and fixes a magnet 31a formed in a ring shape into the support shaft 23 of the bit chuck mechanism 22 supporting the rotary tool 14, and couples the end 23a of the support shaft 23 to the drive shaft 19 of the torque detection device 18 via the coupling 20 so as to be fixed in the rotational direction and elastically displaceable in the axial direction.

In addition, in the part of the support shaft 23 and the coupling 20, protruding support shaft 23 end joint 23a, through spring device 25 and other elastic force holding the protruding part, thereby, in the rotating tool 14 is pressed and displaced, the support shaft 23 elastic force displacement. A magnetic sensor 31b is disposed on the outer peripheral portion of the support shaft 23 in correspondence with the displacement position of the magnet 31a inserted and fixed to the support shaft 23.

Further, similarly to the above, the magnetic sensor 33b, which is configured by combining the magnet 33a and the hall element, and the like, constitutes the lever operation type drive switch 32 that is pressed and displaced by the switch lever 26 provided in the grip portion housing 11 of the electric rotary tool 10 to perform an opening operation. In this case, as shown in an enlarged view in fig. 3, the lever-operated drive switch is provided with a magnet 33a at a displacement portion of the switch lever 26 provided at a part of the grip case 11 of the electric rotary tool 10, and a magnetic sensor 33b is disposed on the grip case 11 side so as to face the magnet 33 a.

The drive switch 30 of the push operation type and the drive switch 32 of the lever operation type configured as described above are arranged such that the magnetic sensors 31b and 33b are connected to the current-carrying circuit of the electric motor 12, respectively, and either one of the operation types is switched via the selection switch 34, and the current-carrying circuit is turned on by the magnetic force sensing operation of the magnetic sensor 31b or 33b of the selected one of the operation types, thereby starting the driving of the electric motor 12.

The selection switch 34 is preferably provided at a mounting base portion of the switch lever 26 of the electric rotary tool 10, for example, as shown in fig. 1, and can perform a switching operation from the control lever operation mode to the push operation mode when the switch lever 26 is detached. On the other hand, when switching from the push operation mode to the lever operation mode, the selection switch 34 is switched to the lever operation mode and then the switch lever 26 is attached, so that the selection state of each operation mode can be easily determined based on the state of the switch lever 26.

Alternatively, as shown in fig. 3, the selection switch 34 is provided with a magnet 35a at a part of the switch lever 26 in a joint portion between the grip case 11 and the switch lever 26 of the electric rotary tool 10, and a magnetic sensor 35b is disposed on the grip case 11 side so as to face the magnet 35 a. Further, an energizing circuit is provided which can be automatically selected and switched, and when the switch lever 26 is detached from the grip housing 11, the driving of the electric motor 12 is started by the pressing operation method, and when the switch lever 26 is attached to the grip housing 11, the driving of the electric motor 12 is started by the lever operation method. With this arrangement, the drive switches 30 and 32 can be constituted by contactless switches, so that occurrence of various noises or abrasion can be prevented, contributing sufficiently to the prolongation of the life of the electric rotary tool and the avoidance of maintenance.

Fig. 4 is a block circuit diagram showing an example of the arrangement of the energizing circuit for starting the driving of the electric motor 12 by the drive switches 30 and 32 and automatically stopping the electric motor 12 by the torque detection device 18. That is, in fig. 4, in the case where a brushless motor is used as the electric motor 12, for example, the drive control circuit 24 combining the electric motor drive circuit 24a and the torque setting automatic stop circuit 24b is built into the electric rotary tool 10 and is connected to an external AC power supply via the AC/DC converter 36. When any operation mode is selected by the selection switch 34, the electric motor 12 is energized from the AC power supply via the AC/DC converter 36, the selection switch 34, and the drive switch 30 or 32, and the electric motor drive circuit 24a of the drive control circuit 24 starts driving of the electric motor 12.

Next, when the rotation driving of the rotary tool 14 in accordance with the driving of the electric motor 12 completes the work such as the screwing work, the load torque generated by the rotary tool 14 is detected by the torque detection device 18, and when the detected load torque reaches a preset value, the automatic stop circuit 24b is set by the torque of the drive control circuit 24 to stop the driving of the electric motor 12, and the operation shifts to a standby state for the next work. The torque detection device 18 may be a system that detects the torque by the known clutch mechanism or a system that detects the torque by the load current.

Fig. 5 is a circuit block diagram showing a modification of the energizing circuit shown in fig. 4. That is, in fig. 5, when a general DC motor is used as the electric motor, the electric rotary tool 10 is configured to be connected to an external AC power source via the control unit 40 combining the AC/DC converter 36 and the torque setting automatic stop device 38 without incorporating a drive control circuit or the like therein. When any operation mode is selected by the selection switch 34, the electric motor 12 is energized from the AC power source via the AC/DC converter 36 of the control unit 40, the selection switch 34, and the drive switch 30 or 32, and the drive of the electric motor is started.

Next, when the operation such as the completion of the predetermined screwing operation by the rotational driving of the rotary tool 14 accompanied by the driving of the electric motor 12 is completed, the load torque generated in the rotary tool 14 is detected by the torque detection device 18, and when the detected load torque reaches a preset torque value, the driving of the electric motor 12 is stopped by the torque setting automatic stop circuit 38 of the control unit 40, and the operation is shifted to the standby state for the next operation.

In the drive switch system of the electric rotary tool according to the present invention, when the screw is removed, the electric motor 12 is rotated in the reverse direction with respect to the normal rotation at the time of the screw tightening operation by operating the forward/reverse changeover switch 28. In this case, when the pressing operation mode is selected for the electric motor 12 and the drive switch is operated, the load torque cannot be detected by the torque detection device 18 when the screw removal is completed, and it is difficult to automatically stop the driving of the electric motor 12 by a torque setting automatic stop device or the like. Further, even when the screw removal is completed, there is a disadvantage that the screw or the screw hole is damaged if the rotary tool 14 is still driven to rotate because the driving of the electric motor 12 is not stopped.

Therefore, in the drive switch system of the electric rotary tool according to the present embodiment, when the forward/reverse switch 28 is operated to switch the electric motor 12 from the forward rotation to the reverse rotation during the work such as removing the screw, the energization circuit is configured such that the drive of the electric motor 12 is disabled according to the pressing operation system, and the energization circuit is configured such that the drive of the electric motor 12 can be started only according to the lever operation system. Therefore, in the case of performing the work such as removing the screw, the operation of the manual lever can be released by the visual and tactile functions of the operator when the removal of the screw is completed, and the driving of the electric motor 12 is stopped, thereby achieving the appropriate and safe work.

Fig. 6 is a diagram showing a modification of the electric rotary tool according to the driving method of the present invention. That is, in the present embodiment, in the case where the torque detection device 18 is a system that performs torque detection by a clutch mechanism, a torque adjustment mechanism that is normally externally operable is provided. In the past, such torque adjustment mechanisms have generally been provided in a position coaxially around the circumference of the support shaft of the rotary tool 14. However, in the case of using the combination of an electric rotary tool and an automatic machine, various mechanisms are arranged in combination around the support shaft of the rotary tool 14. Therefore, when the drive switch system of the present invention is applied, the installation positions of the drive switch and the torque adjusting mechanism are in conflict with the above-described various mechanisms, and therefore, in order to secure these installation spaces, the grip housing 11 needs to be increased in size. Further, when the torque adjusting mechanism is adjusted, it is necessary to remove all of the various mechanisms combined and arranged around the support shaft of the rotary tool 14, which is a drawback that the adjustment work is troublesome and the work of mounting the electric rotary tool is complicated.

Therefore, in the present embodiment, as shown in fig. 6, a setting position of the torque adjusting mechanism 42 for the torque detecting device 18 is disposed to slightly protrude obliquely with respect to the support shaft 23 of the rotary tool 14 protruding vertically downward from the grip housing 11.

Other structures, for example, the structural arrangement of the drive switch and the like are omitted, and basically the same as the structure of the electric rotary tool 10 shown in fig. 1. In the drawings, the same structural parts are denoted by the same reference numerals, and detailed description thereof will be omitted.

Therefore, the electric rotary tool 10 of the present embodiment configured as described above has an advantage that the grip housing 11 can be set to a minimum size, and the operation and maintenance work of the torque adjusting mechanism 42 can be performed without any work such as detaching various mechanisms and the like disposed on the rotary tool 14 side. Similarly, there is an advantage that the operation of attaching and detaching the rotary tool 14 and the maintenance work thereof can be performed without affecting the torque adjusting mechanism 42 at all. In addition, in the arrangement in which the torque adjusting mechanism 42 is inclined with respect to the clutch mechanism of the torque detecting device 18, the shape of the clutch mechanism can be changed locally, so that the arrangement can be easily handled, and does not become a factor of increasing the manufacturing cost.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the scope of the present invention.

Effects of the invention

As apparent from the above embodiment, according to the drive switch system of the electric rotary tool according to the present invention, the electric rotary tool includes: an electric motor; a rotary tool such as a screwdriver bit coupled to an output shaft of the electric motor to perform a work such as screwing; a drive switch for driving the electric motor and starting the operation by the rotary tool; a torque detection device that detects a load torque generated in the rotary tool as the work ends; and a torque setting automatic stopping device which stops driving of the rotary tool when the load torque reaches a preset torque value, wherein in the electric rotary tool provided with the above-mentioned devices, a drive switch of a press operation type which is opened by pressing and displacing a rotary tool against a working object such as a screw by abutting the rotary tool against the working object, and a drive switch of a control lever operation type which is opened by displacing a switch control lever provided in a grip portion of the electric rotary tool are combined with a magnet and a magnetic sensor, respectively, and the magnetic sensors are connected to a current-carrying circuit of the electric motor, and either of the above-mentioned operation types is selected, and the current-carrying circuit is opened by a magnetic force sensing operation of the magnetic sensor of the selected operation type, thus, when the electric rotary tool is used, the drive control by the desired pressing operation mode or lever operation mode can be selectively performed according to the operation contents, so that the efficiency of the tightening operation of the screw or the like can be constantly improved, and the operation can be simplified and the safety can be sufficiently improved.

In the drive switch system of the electric rotary tool according to the present invention, the drive switch of the press operation system is arranged to be coupled to a support shaft supporting the rotary tool by a coupling so as to be elastically displaceable in the axial direction, a magnet is provided at the displacement portion of the support shaft, a magnetic sensor is disposed on the outer peripheral portion of the support shaft so as to face the magnet, and the lever-operated drive switch is disposed, a magnet is provided at a displacement part of a switch lever provided at a part of a grip part housing of an electric rotary tool, and a magnetic sensor is disposed on the side of the grip housing facing the magnet, and a selectable selection switch is provided to form a current-carrying circuit for starting the driving of the electric motor in any one of the operation modes, the drive switches can be easily provided for one electric rotary tool in a push operation mode and a lever operation mode, respectively. In particular, when a brushless motor is used as the electric motor, the drive switch can be housed in the grip portion case of the electric rotary tool together with all of the drive control circuits of the electric motor, and the advantages of a long life due to the total surface non-contact, maintenance-free, and simplified operation can be achieved.

Further, the drive switch system of the electric rotary tool according to the present invention is configured such that a forward/reverse switch operable externally is provided in a part of a grip portion housing of the electric rotary tool, and when the electric motor is switched from forward rotation to reverse rotation during a work such as removal of a screw, a conduction circuit in which the drive of the electric motor by a pressing operation is disabled is configured, and a conduction circuit in which the drive of the electric motor can be started only by a lever operation system is configured.

In the drive switch system of the electric rotary tool according to the present invention, when the clutch mechanism is used as the torque detecting device incorporated in the grip housing, the torque adjusting mechanism acting on the clutch mechanism is disposed to slightly protrude obliquely with respect to the support shaft of the rotary tool protruding vertically below the grip housing, whereby the grip housing can be set to a minimum size, the drive switch and the torque adjusting mechanism can be easily installed in parallel, and the operation and maintenance work can be smoothly performed without affecting the rotary tool and the torque adjusting mechanism, and the electric rotary tool with easy operation can be obtained.

Claims (4)

1. A drive switch system of an electric rotary tool, the electric rotary tool is provided with: an electric motor; a rotary tool for screwing the screw, coupled to an output shaft of the electric motor; a drive switch for driving the electric motor and starting the operation by a rotary tool; a torque detection device that detects a load torque generated in the rotary tool as the work ends; and a torque setting automatic stop device which stops the driving of the rotary tool when the load torque reaches a preset torque value,

a drive switch of a press operation type for performing an opening operation by pressing and displacing a rotary tool against a screw operation target, and a drive switch of a lever operation type for performing an opening operation by pressing and displacing a switch control lever provided in a grip portion of an electric rotary tool, are combined with a magnet and a magnetic sensor, respectively;

the magnetic sensors are connected to an energizing circuit of the electric motor, the energizing circuit being configured such that the electric motor is energized by the magnetic sensor which is operated magnetically by a pressing operation, and the electric motor is energized by the magnetic sensor which is operated magnetically by a lever operation, and the magnetic sensor is connected to the energizing circuit of the electric motor, and

in a joint portion between a grip case and a switch lever of an electric rotary tool, a magnet is provided in a part of the switch lever, a magnetic sensor is disposed on a side of the grip case opposite to the magnet, and a selection changeover switch is provided for automatically selecting and switching an energizing circuit for starting driving of an electric motor by a pressing operation mode when the switch lever is removed and starting driving of the electric motor by a lever operation mode when the switch lever is attached, respectively.

2. The drive switch system of an electric rotary tool according to claim 1, wherein a brushless motor is used as the electric motor, and a drive control circuit of the brushless motor and an energization circuit thereof are all housed in a grip portion case of the electric rotary tool.

3. The drive switch pattern of the electric rotary tool according to claim 1,

an externally operable forward/reverse switch is provided in a part of a grip housing of an electric rotary tool, and when an electric motor is switched from forward rotation to reverse rotation, an energizing circuit is configured in which the driving of the electric motor by a push operation method is disabled, and an energizing circuit is configured in which the driving of the electric motor can be started only by a lever operation method.

4. The drive switch pattern of the electric rotary tool according to claim 1,

in the case of using a clutch mechanism as a torque detection device incorporated in a grip housing of an electric rotary tool, a torque adjustment mechanism acting on the clutch mechanism is disposed to slightly tilt and project from a support shaft of the rotary tool projecting vertically downward from the grip housing.